While it is possible to perform slow shutter photographing in which trajectories of light, water flows, and movements of objects are recorded by lowering a shutter speed, there has been a need to fix image pickup apparatuses such as a camera using tripods or the like for preventing blurring during exposure. Consequently, time and effort had been necessary for users due to loads of carrying and setting tripods, restrictions on compositions, and the like.
In this regard, for example, Patent Document 1 proposes a method of consecutively photographing images having a short exposure time and synthesizing those images to obtain a quasi-slow shutter effect. In this method, however, movements of objects cannot be captured when the shutter is shut, and thus the synthetic image has been unnatural.    Patent Document 1: Japanese Patent Application Laid-open No. 2012-83848